The deal is the first under new rules for Major League Baseball teams buying players from Nippon Professional Baseball. The “release fee” paid to the player’s Japanese club is now capped at $20 million, the price the Yankees will pay to Rakuten Golden Eagles. In the past these bids were unlimited. The Red Sox paid $51.11 million to the Seibu Lions for the right to negotiate with Daisuke Matsuzaka in 2007 and signed him for $52 million over six years. In 2012, the Texas Rangers paid $51.7 million to the Nippon-Ham Fighters for Yu Darvish and signed him for six years and $60 million.

The fates of those two pitchers illustrate the uncertainty of buying talent from Japan. Matsuzaka put together one great season in 2008 and has been mediocre-to-terrible since. Darvish finished second on the American League Cy Young ballot last season and led the majors in strikeouts. But as this Bloomberg Sports breakdown of the history of Japanese pitching imports notes, Darvish hasn’t escaped a Matsuzaka-style collapse quite yet. “And if he does,” the report notes, “he’ll be the first posted pitcher to do so.” (Part of the problem, by the way, in evaluating Japanese players is that they play with a smaller ball.)

The Yankees know these risks as well as anybody. In 2007 they paid a $26 million fee for Kei Igawa and signed him for $20 million over five seasons. He logged not quite 72 innings with the Yankees before being booed off the field and sent to the minors to finish his contract in a sad, lucrative baseball purgatory.

By all accounts, however, Tanaka is closer to Darvish than he is to Igawa. Bloomberg Sports projects that Tanaka will post a 13-9 record with 152 strikeouts and a 3.62 ERA next season for the Yankees. This contribution moves their chances of winning the American League East from 36 percent to 42 percent. If that’s right, the Yankees will call his $22 million salary a bargain.